Unexpected behaviour when processing more than one entity.

[vimnux]

local ent1 = { foo = true }
local ent2 = { bar = 1 }

local tiny = require("tiny")
local world = tiny.world()

tiny.addEntity(world, ent1)
tiny.addEntity(world, ent2)
tiny.refresh(world)

local sys = tiny.processingSystem({ isSystem = true })
sys.filter = tiny.requireAny("foo", "bar")

function sys:process(e)
  print("foo is: " .. tostring(e.foo))
  print("bar is: " .. tostring(e.bar) .. "\n")
end

tiny.addSystem(world, sys)

local filter = tiny.requireAll("isSystem")
tiny.update(world, 1, filter)

Results in:

foo is: true
bar is: nil

foo is: nil
bar is: 1

Instead of the expected:

foo is: true
bar is: 1

The issue also occurs when processing 2 entities after selecting them with:

tiny.setSystemIndex(world, system)

or:

tiny.requireAll (...)

Is there a "tiny-ecs way" to get the expected behavior ?

Or do I have to add checks for nill values like:

local ent1 = { foo = true }
local ent2 = { bar = 1 }

local tiny = require("tiny")
local world = tiny.world()

tiny.addEntity(world, ent1)
tiny.addEntity(world, ent2)
tiny.refresh(world)

local sys = tiny.processingSystem({ isSystem = true })
sys.filter = tiny.requireAny("foo", "bar")

function sys:process(e)
  if e.foo ~= nill then
    print("foo is: " .. tostring(e.foo))
  end
  if e.bar ~= nil then
    print("bar is: " .. tostring(e.bar) .. "\n")
  end
end

tiny.addSystem(world, sys)

local filter = tiny.requireAll("isSystem")
tiny.update(world, 1, filter)

To get the values of components "foo" and "bar" as:

foo is: true
bar is: 1

I encountered the issue in both the latest git and the 1.3-3 release.